Posted
by
Soulskill
on Saturday September 15, 2012 @12:40PM
from the pretty-pictures dept.

Techmeology writes "A team from IBM in Zurich has published images of molecules that are detailed enough to show the lengths of atomic bonds. 'The IBM team's innovation to create the first single molecule picture, of a molecule called pentacene, was to use the tip to pick up a single, small molecule made up of a carbon and an oxygen atom. This carbon monoxide molecule effectively acts as a record needle, probing with unprecedented accuracy the very surfaces of atoms. It is difficult to overstate what precision measurements these are. The experiments must be isolated from any kind of vibration coming from within the laboratory or even its surroundings. They are carried out at a scale so small that room temperature induces wigglings of the AFM's constituent molecules that would blur the images, so the apparatus is kept at a cool -268C.' This allows an analysis of imperfections in the molecular structure (abstract). The team plans to use the method to examine molecules of graphene."

the writeup describes an earlier paper, not the recent one that was in Science. they previously showed that you can look at planar molecules like pentacene with afm, here they showed that you can see minor differences in the bond lengths to distinguish single/double bonds.

Pauling is really great, I agree that he should be more well-known (I, myself, am partial to Dirac, who predicted the existence of anti-matter out of pure math). But you have to realize that Newton and (maybe to a lesser degree) Einstein contributions were of another class.

Newton took Galileo's ideas -- that things tend to keep moving if they're left alone -- and built a whole mathematical theory on top of that, inventing calculus in the process. In a sense, it was the beginning of what we today call Physics.

Einstein was the first to notice (and convinced everyone) that the Lorentz transformation is not just a mathematical trick, it's the very way the space and time works. This itself was not that impressive, he was just giving a "new spin" on what everyone had already observed. But then he went on to show that the "right way" to understand gravity is by noting that it's just a side-effect of mass bending the space and time -- this has lots of consequences that were unknown at the time, like gravity bending light, gravity making time pass at different rates, and a lot other stuff, all of which turned out to be right.

Quantum Mechanics and its implications (like the electron shell), on the other hand, were discovered bit by bit by a lot of different people. That's why no one is hugely famous for it (even though there are certainly big names like Planck, Einstein, Bohr, Heisenberg, Born, Schrodinger, Dirac, Pauli, etc.).

Well, it brings us a small step closer anyway. There's a world of difference between "looking" at something and building it, though the technology to manipulate the probe may translate.

As for a space elevator we still need to discover a material strong enough before manufacturing it becomes a serious consideration, at least for the traditional "beanstalk past geostationary" style. Even multiwalled carbon nanotubes are barely strong enough to support their own weight in such a configuration, and you probably want at *least* a 2x-3x safety factor, and we'll likely need to come up with something pretty exotic to top the strength of a C-C bond.

Well tunnel microscopes can also be used for building stuff, perhaps the same method could translate to these as well. And a material only needs to be able to support its own strength and a bit more: after that, safety is just a matter of thickness.

It's not quite so simple - both weight and strength scale with the cross-sectional area, so if it can support say 10% more than its own weight then no matter how thick you make it it will still only support 10% more than its own weight. And a 10% safety factor is completely unacceptable on an engineering product of this scale - the cable that could wrap around the world if it broke near geosationary, where the load would be at its greatest.

Do you have a source for this assertion? Everything I've seen suggests that while graphene is far better at lending it's strength to composite materials the substance itself has roughly the same strength, which is to be expected, nanotubes are after all essentially rolled-up lengths of graphene. And composite materials aren't really relevant in this situation unless the strength:mass ratio exceeds that of the pure material.

Probabilistically speaking, the position of electrons is probably what results in a sphere shape. Electrons move too fast to be in any single position at any point in time (at least, deterministically), so it appears as a spherical/elliptical cloud around the nucleus at a given energy level.

I wonder if it's possible that electrons don't really even exist as small, spherical particles that orbit the nucleus, as we're taught in school, but instead are something else entirely, and it's just convenient for us to model them as such.

Nice. AFMs have been imaging atoms for about two decades (and yes, they do look like spheres). Being able to see intermolecular bonds is a big step forward.

AFMs are amusing. The idea is so simple - mechanically scan atoms with a really sharp point. Everyone had assumed that you'd have to scan atoms with electron beams (as with electron microscopes) or X-rays (as with X-ray diffraction), using some particle much smaller than the atoms being scanned. Then Quate and Gerber figured out how to scan atoms mechanically. Which sounds like a really silly idea, but works.

An AFM works like a mechanical record player. It's a pointy needle on a positioner made using piezoelectric elements. Raster scan signals are applied to the positioners to get a classic TV-type scan, and the third axis has its position measured and is servoed until the point touches the sample. Height measurements come out. Basic AFMs aren't very complicated or very big.

It took a surprisingly long time to come up with this idea. It was invented in 1986. One probably could have been built in 1946, and certainly in 1966.

You're right partially, but AFMs don't quite work that way. The mechanical "probe" scrapes the surface (only one atom in contact usually), but the position is not measured using piezos. Piezoelectric materials move the base below the sample to atomic accuracy, but the position of the cantilever is measured by reflecting a laser off the cantilever to a sensor. The sensor is split in four quandrants and measures the deflection of the cantilever.

This rather surprised me. Given that carbon has p-orbitals, and that those orbitals should be locked into position by being used to bond adjacent atoms, I'd have thought the non-spherical orbitals to be visible. I concude that even A-level chemistry textbooks lie.

It is is good to see this kind of basic research is still being done. Even as Hewlett Packard has gutted its research capabilities and looks set to suit to its corporate grave, blue-chip IBM shows that it still understands the need for discovery. Though it is perhaps indicative that this team is decidedly not American...

I worked in IBM until recently (I was there for 4 years). Their R&D teams that do indeed do computer science research (databases, AI, server design), but most of the teams focus on fundamental research. Chip fab and storage (which is mostly fundamental physics & chemistry research) is one where they spend a lot. They also spend a lot of money in emerging tech (Solar panels, road traffic management, lot other strange stuff). I dont see many products coming out these, and I have no idea why they do th

Yes but IBM Zurich is quite special, even within IBM. Funding scientists in Switzerland is extremely expensive, perhaps the most expensive place in the world to perform basic research. There is no global minimal salary, but in many activity branches the minimum salary for a full time job is a bit above SF3000 (over $3000). You have to take out some contributions, taxes, and pay your health insurance, but even after that, you are left with a considerable amount of dough.